Scan Display Data Driver Short Circuit Detection
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Solution Overview
Problem
Conventional methods for driving LED displays in a line scan manner can cause short circuit caterpillar phenomena, leading to degraded display quality due to unexpected light emission and cross-channel coupling issues.
Innovation Solution
A scan-type display apparatus with a common cathode configuration, incorporating a data driver that includes current drivers and detectors to identify short circuits by analyzing voltage and timing signals, thereby preventing the short circuit caterpillar phenomenon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If line scan driving method is used for LED display, then ghosting phenomenon and cross-channel coupling problems are alleviated, but short circuit caterpillar phenomenon occurs degrading display quality
Solution Approach 1:
The patent applies preliminary action by performing short circuit detection before the short circuit caterpillar phenomenon can degrade display quality. The detection circuit monitors LED status in real-time during the line scan driving process, enabling early identification of short circuits before they propagate through the display and cause visible degradation.
Solution Approach 2:
The patent implements feedback through a detection circuit that continuously monitors the status of LEDs and provides real-time information about short circuits. This feedback mechanism allows the system to identify and respond to short circuit conditions dynamically, preventing the caterpillar phenomenon from developing and maintaining display quality.
2Productivity
If conventional line scan driving is implemented, then LED array can be driven efficiently, but short circuit detection capability is lacking
Solution Approach 1:
The patent merges the driving function and detection function into a unified system. The detection circuit is integrated with the line scan driving circuitry, allowing simultaneous LED driving and short circuit monitoring without requiring separate independent systems. This combination maintains driving efficiency while adding detection capability.
Solution Approach 2:
The patent introduces an intermediary detection circuit that acts as a mediator between the driving signals and the LED array. This intermediary component monitors the electrical characteristics during normal driving operations, enabling short circuit detection without interfering with the efficient line scan driving process.
Data Source
AI summary
A scan-type display apparatus includes an LED array and a data driver. The LED array has a common cathode configuration, and includes multiple scan lines, multiple data lines and multiple LEDs. The data driver includes multiple data driving circuits, each of which includes a current driver and a detector. The current driver has an output terminal connected to the data line corresponding to the data driving circuit, and outputs one of a drive current and a clamp voltage at the output terminal of the current driver based on a pulse width control signal. The detector is connected to the current driver, and generates a detection signal that indicates whether any one of the LEDs connected to the data line corresponding to the data driving circuit is short circuited based on a detection timing signal and a feed-in voltage related to a voltage at the output terminal of the current driver.